Subject: Undelivered Mail Returned to Sender
From: [email-masked] (Mail Delivery System)
To: [email-masked]
Date: Tue, 21 Mar 2023 12:58:27 +0100 (CET)

This is the mail system at host mx4.cloud4u.solutions.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<info@kuw-kaelte-klima>: Host or domain name not found. Name service error for
    name=kuw-kaelte-klima type=A: Host not found